Merseyside Police detained a 46-year-old at an address in Knowsley Village.

Another five men – two Colombians, two Peruvians and a Spaniard – were detained by Spanish police after they traced the delivery of a dummy consignment of charcoal to an industrial-sized drug production lab outside Valencia which masqueraded as a legitimate business.

Greg McKenna, NCA Regional Head of Investigations, said: “We believe the company was a front for a industrial-sized lab where cocaine was extracted from pallets and charcoal, processed and repackaged for onward distribution across Europe.

“This seizure of cocaine, the shutting down of the lab and the eleven arrests will have disrupted criminal activity across the whole of Europe.”

The four men arrested in Liverpool were bailed pending further enquiries, while the two Liverpool men in Dubai remain in custody.

The five men in Spain are also in custody.

The Grosvenor House’s twin towers are one of the most recognisable landmarks in the Dubai Marina. There are a number of apartments within the hotel complex that are rented out.